Mold



Oct. 18, 1927.

c. VAUGHAN MOLD Original Filed Feb. 11, 1924 4 Sheets-Sheet 1 anuewro o aktoww Cl. VAUGHAN MOLD 4 Sheets-Sheet 2 Original Filed Feb. 11, 1924.

4 sheets sheet 3 C. VAUGHAN MOLD a H 1) c-ntoz @H'o an;

Original Filed Feb. 11

Oct. 13, 1927.

Oct. 18, 1927. 5,727

C. VAUGHAN MOLD Original Filed Feb. 11? 1924 Sheets-5heei 4 anucwi'op can/m4 m x fi x J5 ZZWL and from each other and adapted to be positioned in engagement with each other to complete the mold cavity over the back member 7. The back member 7 of the mold is detachably secured at the center of the casing 1 to the bottom and back walls 2 and 3 thereof by mean-s of screws 10, and has its outer face curved to form the outer wall of the molt cavity. The side sections 8 and 9 have base portions 11 and 12 sli'dably mounted upon the bottom and back walls 2 and 3 of the casing 11, and are retained in the casing and guided by guide strips 13 and 14 secured along the lower edge of the bottom 2 and the upper edge of the back wall 3 of the casing, respectively. The inner portions of the side sections are adapted to engage woppositc sides of the fixed mold section '7 ahd have overhanging outer portions adapted to engage with each other centrally over the back member 7 and close the inncr side of the mold cavity when the. sidesections are adjusted into engagement with the fixed mold section 7. At the upper ends thereof the sections 8 and 9 are provided with complementary tapering grooves leading to the recessed portions and which when the sections are secured together, form the gate and funnelshaped sprne cavity 15.

Figs. 5 and 6 show the brake shoe casting which is formed in the mold, this casting having a wide flanged. outer portion 16 forming the engaging face and a web '17 projecting inwardly from. the outer portion. The outer flanged portion 16 is formed against the back member 7 of the mold and the complemental cavities of the side sections are shaped to form the inner faces of the flanges and the web portion 17. The shoe is formed at one end with an eye 18 to receive a pivot pin, and adjacent the centerwith an elongated opening 19 to receive a guide pin, the openings 18 and 19 being reinforced with suitable bosses. At the end opposite the eye 18 the web of the casting is formed to provide spaced ears, forming a crotch 20 in which a link may be pivoted.

The outer face of the wide flanged outer portion 16 of the casting is formed against the fixed mold member 7, and the side'sections 8 and 9 of the mold are so formed that when the sections are brought together a mold cavity corresponding to the complete casting is formed. The section 8 carries a core pin 21 which is slidahly mounted in a transverse opening therein and adapted to be pushed into the mold across the cavity to form the eye 18 at the end of the casting, the section 8 carrying also a slidably mounted core pin 22, shaped to form the elongated opening 19, recesses being formed in the inner faces of the mold sections around the core pins to form the bosses. The crotch 20 is formed by means of a core bar 23 which is mounted upon the inner face of the mold section 9 and lies, when the mold is closed, partly in a groove 24 in the section 9 and partly in a groove 25 in the section 8. The groove 24 is deeper than the groove 25, and the core bar 23 has a thickened outer portion fitting in the groove 24:. The core bar 23 isretained in the groove 25 by means of a block 26 which fits in an elongated slot 27 in the bar 23. The block 26 is rigidly Securcd to th bottom of the groove 24 by means of screws 28 and has a retaining flange 29 at its outer end which engages in recesses along the edges of the slot 27 on the inner face of the bar 23, the outer face of the block 26 being flush with the inner face of the bar 23. The inner end of the core bar 23 is centered with respect to the mold cavity and has its inner end rounded to form the bottom i of the groove between the ears, forming the crotch 20. The core bar 23 is provided with a rack 30 on its under side, which is engaged by a pinion 31 which carries a hand wheel 32 by means of which the core bar may be moved in 01' out, the inward movement of the core bar being-limited by the block 26 which is so positioned that when the core bar is in its innern'iost position it will be in proper position for forming the crotch 20 in the casting. The core members 21 22 and 23 are all adjusted into the mold cavity before pouring and are withdrawn from the casting before the mold is opened, each of the core members being slightly tapered to facilitate their withdrawal from the casting For clamping the mold sections 8 and 9 together with adequate pressure, screws 33 are attached thereto and project through slots 34 in the opposite end walls 4 and 5 of the mold supporting casing. For moving the screws 33 longitudinally to apply pressure to the mold sections, each screw has a nut 35 which has an external groove 36 fitting in the slot 34, whereby the nut may be rotated-and has a thrust end wall to hold it against longitudinal ontward or inward movement in clamping the mold sectiorisand separating them. Each nut 35 has a crank handle 37 by means of which it may be rotated to shift the mold section, and an oppositely extending weighted counterlmlance arm 38 which enables the nuts to be given a rapid spin to impart quick movement to the moldscctions.

The mold sections are. all dctachahlv mounted in the supporting casing so that they may he rcadilyrcluhved and replaced by mold sections forcastings of dill ercnt size or shape. To facilitate the quick removal of the side sections the screws 33 are connected to the sections by means of pivots 139i and the grooves 36 are considerably wider than the thickness of the end walls of the casing so that when the nut is loosened the screws may be readily swung up outof the slots 34 and freed from the casing.

bearing against the thus permitting the thi When the metal is poured, it enters through the funnel-shaped sprue cavity and flows rapidly to the lowermost end of the casting, the mold cavity being progressively filled from the lowermo tend to the gate Which is near the highest portion oi the mold. cavity, just suiiicient metal being poured into the sprue cavity and through the gate to insure flow to the extreme top of the mold cavity. ,The metalis thus caused to freeze progressively from the lower to the upper end of the casting, the shrinkage of the metal during cooling being progressively taken up by the lion of hotter metal from above.

It will thus be seen that by properly proportioning the sprue cavity and the gate or opening between-the sprue cavity and the mold cavity the sprue cavity may be very small and contain very little excess metal, as it is only necessary to furnish a sailicient head to completely fill the mold and to provide molten metal for feeding only a small portionof the metal in the casting near the gate,

Difficulty has heretofore been experienced in forming from aluminum alloys castings" of shapes similar to that shown herein, due to the factthat the central portion of the Wide flanged outer portion 16 of the casting does not cool as fast as other thinner portions of the casting. This sometimes results in uneven outer surfaces, due to shrinkage of this central portion caused by slower freezing of this. portion and interference with flow of metal thereto by freezing of adjacent thinner portions. To avoid this difficulty I make the longitudinal central portion of the back mold member 7 a good conductor of .heat and outside the longitudinal central portion I make this back member a poorconductor of heat. This I accomplish vby leaving acentral strip along the com ter of the inner-face of the member 7 uncoatecl or coated with any suitable coating, such as a graphite composition which will not appreciably retard conduction of heat Outside the central strip 40, which is located opposite the Web of the casting, I apply preferably a suitable coating ll such as a clay mixture, which is a poor conductor of heat. By this means the cooling of the thicker. portion of the casting is facilitated f with respect to the adjacent flanges. and the cooling of the adjacent flanges retarded, lter portion of the casting to solidify first and preventing shrinkage away from the moldl as the necessary feeding of the inner portion of the casting is accomplished by. the incoming hot metal from thegate, the mold, as mentioned above, being designed so that the casting freezes progressively from one end to the gate in important feature of the invention 'tion, of the similar crank 37 the provision of means whereby the mold may be opened while the casting is still quite hot without danger of marring or deforming the casting. To this end means is provided for holding the casting upon the curved backing member While the side sections are separated sothat the casting is heldegainst distortion when it is still quite hot. To this end upper and lower ejector pins 42 and 43 adapted to engage the ends of the casting and a middl ejector pin {l4 adapted to engage the middle of the casting are rigidly secured to the side Wall 5 of the supporting or and proiect through the section 9, the pins being of such length that their inner ends are flush with the inner surface oi the section Q whenthe same is in operative position. The lower ejector pin 43 lies opposite the core pin 21 which forms the eye 18 inthe lower end of the casting, and is of sufliciently greater diameter than the pin 21 to engage solidly with the boss surrounding the eye 18 in the casting.

In opening the mold, the core pins 21 and 22 are withdrawn and 1' the mold section 8 is retracted quickly by the crank 37 and the nut 35, and the casting is held against the mold by the core pins The-core 23 is then withdrawn by turning the hand Wheel 32, and the mold section 9 is retracted by operaand nut 35, the fixed ejector pins 42, 4:3 and ll holding the captting in place uponthe fixed section 7 of the mold while section 9 is being Withdrawn therefrom. The casting is thus held against distortion While the mold sections are being retracted and may be removed from the mold.

Furthermore, it is to he understood that the particular forms of apparatus shown and described and the particular procedure set forth are presented for purposes of explanation and illustration and that various modifications of said apparatus and pro ccdure canbe made without departing from my invention as defined in the appended claims. l

l Vhat I claim is l. A mold for casting shapes having alongitudinal curvature, comprising a fixed scction adapted to form the outer, convex face of the curved c sting side sections movable toward and from the fixed section and adapted,=to he clamped together over the titted section to form the mold cavity, means for supporting said sections in. a position such that the mold cavity is inclined downwardly from oneend to the other and means forming a at the top of the mold.

52. A mold for *asting brake shoes cornprising fixed section having an inner curved .t'acc side sections adapted to be together over said fixed section dc sections cooperating with the fixed oi the brake shoe and with each other to form the Web thereof, core pins carried by one of the sections for forming holes in the web, and means for; retaining the casting on the fixed section while one of the side sections isbeingwithdrawn.

3. A mold comprising a pair of movable side sections having complementary depress1ons to form a mold cavity, said sections having meeting edges adapted to contact along the center plane of the casting and extending outwardly along said plane to form tlat faces, alined grooves in said flat faces extending into said mold cavity, and'a core plate slidable in said grooves when said sections are assembled and adapted to extend into said mold cavity.

4. A mold comprising niovably mounted side sections having complementary depressions adapted when the mold is assembled to form a mold cavity and flat faces adapted to contact along the center plane of the castporting casing having a bottom and back wall. a stationary mold section detachably secured to said bottom and back wall, a air of mold side sections slidably mounte in the casing on opposite sides of the fixed mold section, said slidable and fixed mold sections cooperating when in assembled relation to enclose a mold cavity, means for moving said slidable mold sections, and means for securing said slidable mold sections in cooperative relation with said fixed mold section.

6. A mold for casting longitudinally curved shapes having convex outer faces, which comprises a mold casing, a mold section having a concave face and secured to the mold casing. mold sections slidably mounted iii-the casing for movement toward and from said concave section, guides on the casing for guiding said movable sections, means carried by said movable sections for engagement with the casing to shift said sections, said mold casing being mounted as an entirety in a supporting stand, so that plurality of mold sections,

the wall of sai one end of the lon itudinally curved mold cavity is substantia ly lowermost.

7. A mold for casting a longitudinally "curved shape having a convex outer face comprising a mold section provided with a concave inner face for forming said convex face of the casting, mold sections on either side of said concave section and having recesses therein to cooperatively form withsaid concave mold section the complete mold cavity, said concave mold section. having portions thereof coated to retardthe escape of heat from the casting, and having a porltion to relatively facilitate the escape of ieht.

8. A permanent mold having its cavity forming wall coated in part with a substance to retard heat transfer and coated in art with a substance to relatively facilitate eat transfer.

- 9. ,A permanent moldadapted for use in forming castings from metal of relatively high crystallization shrinka e and relatively low freezing point, said mo I said mold sec to enclose a mold cavity, mold cavity being coated in part with material to retard heat transfer,

tions cooperatin and coated in part with material to relative- 1y facilitate heat transfer. a

10. A permanent mold for use in forming 'castings havinga longitudinal curvature from metal of relatively high crystallization shrinkage and relatively low melting point, said mold comprising, in combination, a back mold section having an inner curved face adapted to form the outer convex face of the curved casting, side mold sections arranged to be disposed in assembled position over said back section, said side sections being provided with complementary recesses forming with said back section a mold cavity inclining downwardly from one end to the other, said recesses forming also a relatively small sprue cavity extending upwardly from adjacent the upper end of said mold cavity and a relatively small gate intermediate and connecting said mold and sprue cavities, means for securing said mold sections in molding position, and ejecting means associated with one of said side sections whereby a casting may be disassociated from said section.

In testimony whereof, I hereunto aflix my signature.

' CONRAD VAUGHAN.

(1 comprising a 

